I can't recall which, but I remember reading about a language with a relative complement operator on types. The idea is, where T is a set of types, then:

T \ {A, B, ...}

would be all types in T *except* A, B, ....

I think maybe there could be a type variable Except that could be used like:

Except[T, A, B, ...]

where T is a type variable. (Other name ideas: Complement, Difference).

[ERROR]: Your autotools build scripts are 200 lines longer than your program. Something’s wrong.

On Jul 25, 2016 6:58 PM, "Greg Ewing" <greg.ewing@canterbury.ac.nz> wrote:
Bar Harel wrote:
Soon enough we'll have NotBytesSequence, NumericSequenceWithoutFloat and BuiltinNotCustomMadeIterable.

Is there some way we could provide a general way of
constructing a "but not" ABC, so that people could
build their own combinations as needed?


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